NR Seals
NR is the abbreviation for natural rubber.
The raw material is extracted from the milky sap of rubber plants and is primarily important as a base material for other rubber compounds in the entire elastomer industry.
NR/SBR is a compound consisting of natural and styrene-butadiene rubber and is the most widely used rubber compound for a wide range of the simplest applications, thanks in part to the excellent mechanical and dynamic properties of this material.
NR materials available from Rehm-Dichtungen Ehlers GmbH
We purchase part of the NR as rolls and sheets from the manufacturer Semperit. Here we divide the material qualities into three ranges that are suitable for different applications.
The NR/SBR qualities A9506, A618 and A621 are referred to as Commercial Standard quality. These are qualities that consist mainly of SBR components and only a very small proportion of NR. These qualities are suitable for simple applications and are in the lower price segment. A9506 can be supplied with one or two glass fibre inserts on request. This increases the tensile strength somewhat. The qualities A618 and A621 are tested PAH-free (BfR XXI category 1 and FDA 21 Food and Drugs Part 177.2600) and are suitable for use in the food sector.
A160, A560 and A654 are classified as para grades. They consist almost exclusively of NR and therefore have the best mechanical properties. The wear protection grade A590 contains slightly more SBR than the Para grades. This makes them less expensive, but they still have good mechanical values and excellent abrasion values.
In addition to Semperit NR/SBR, we also source various import qualities.
Paraqualities
A160 NR
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 40 +-5 |
| Density [g/cm³] | ISO 1183 | Approx. 1.08 |
| Tensile strength [N/mm²] | ISO 37-S2 | 15 |
| Elongation at break [%] | ISO 37-S2 | 550 |
| Abrasion [mm³] | ISO 4649-A | 110 [5N] |
Approvals and certifications:
- highly elastic
- Excellent mechanical properties
- PAH - fully complies with GS Cat. 3
- Corresponds to WDK guideline 2201
A560 NR
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 40 +-5 |
| Density [g/cm³] | ISO 1183 | Approx. 1.06 |
| Tensile strength [N/mm²] | ISO 37-S2 | 18 |
| Elongation at break [%] | ISO 37-S2 | 600 |
| Abrasion [mm³] | ISO 4649-A | 110 [5N] |
Approvals and certifications:
- highly elastic
- Excellent mechanical properties
- PAH - fully complies with GS Cat. 3
- Corresponds to WDK guideline 2201
Materials for food contact
A618 NR/SBR light 45 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 45 +-5 |
| Density [g/cm³] | ISO 1183 | Approx. 1.28 |
| Tensile strength [N/mm²] | ISO 37-S2 | 12 |
| Elongation at break [%] | ISO 37-S2 | 550 |
Approvals and certifications:
- Food quality
- BfR XXI Category 1 (For consumer articles that come into contact with foodstuffs for longer than 24 hours when used as intended)
- FDA 21 Food and Drugs Part 177.2600 for repeated contact with aqueous foodstuffs
- PAH - fully complies with GS Cat.3
- Corresponds to WDK guideline 2201i
A621 NR/SBR light 65 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 65 +-5 |
| Density [g/cm³] | ISO 1183 | Approx. 1.43 |
| Tensile strength [N/mm²] | ISO 37-S2 | 8 |
| Elongation at break [%] | ISO 37-S2 | 380 |
Approvals and certifications:
- Food quality
- BfR XXI Category 4 (For consumer goods that are in contact with the food for a very short time or only with a very small surface area).
- FDA 21 Food and Drugs Part 177.2600 for repeated contact with aqueous foodstuffs
- PAH - fully complies with GS Cat.3
- Corresponds to WDK guideline 2201
Commercial standard qualities
A9506 NR/SBR 70 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 70 +-7 |
| Density [g/cm³] | ISO 1183 | Approx. 1.46 |
| Tensile strength [N/mm²] | ISO 37-S2 | 4 |
| Elongation at break [%] | ISO 37-S2 | 200 |
Approvals and certifications:
- Standard quality
- For low requirements
- Corresponds to WDK guideline 2201
- SVHC-free
Wear protection qualities
A590 NR/SBR 60 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 60 +-1 |
| Density [g/cm³] | ISO 1183 | Approx. 1.15 |
| Tensile strength [N/mm²] | ISO 37-S2 | 15 |
| Elongation at break [%] | ISO 37-S2 | 400 |
Approvals and certifications:
- Technical sealing plate
- Excellent mechanical properties
- Conditionally weather resistant
- antistatisch (spezifischer Durchgangswiderstand nach ASTM D 991 < 1 MegaOhm*cm)
- Corresponds to WDK guideline 2201
- SVHC-free
Import qualities
NR/SBR 50 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 50 +-1 |
| Density [g/cm³] | ISO 1183 | Approx. 1.4 |
| Tensile strength [N/mm²] | ISO 37-S2 | 3 |
| Elongation at break [%] | ISO 37-S2 | 250 |
NR/SBR 70 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 70 +-10 |
| Density [g/cm³] | ISO 1183 | Approx. 1.5 |
| Tensile strength [N/mm²] | ISO 37-S2 | 3 |
| Elongation at break [%] | ISO 37-S2 | 200 |
NR/SBR 70 Shore with insert
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 70 +-10 |
| Density [g/cm³] | ISO 1183 | Approx. 1.5 |
| Tensile strength [N/mm²] | ISO 37-S2 | 3 |
| Elongation at break [%] | ISO 37-S2 | 200 |
NR/SBR 70 Shore with insert, fabric patterned on one side
Technical data sheet:
NR/SBR 70 Shore with insert, fabric patterned on one side
Properties:
| Hardness [Shore A] | ISO 7619-1 | 70 +-10 |
| Density [g/cm³] | ISO 1183 | Approx. 1.5 |
| Tensile strength [N/mm²] | ISO 37-S2 | 3 |
| Elongation at break [%] | ISO 37-S2 | 200 |
NR/SBR 80 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 80 +-10 |
| Density [g/cm³] | ISO 1183 | Approx. 1.4 |
| Tensile strength [N/mm²] | ISO 37-S2 | 3 |
| Elongation at break [%] | ISO 37-S2 | 200 |
NR/SBR light 50 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 50 +-10 |
| Density [g/cm³] | ISO 1183 | Approx. 1.5 |
| Tensile strength [N/mm²] | ISO 37-S2 | 5 |
| Elongation at break [%] | ISO 37-S2 | 300 |
NR/SBR light 65 Shore
Technical data sheet:
Properties:
| Hardness [Shore A] | ISO 7619-1 | 65 +-10 |
| Density [g/cm³] | ISO 1183 | Approx. 1.5 |
| Tensile strength [N/mm²] | ISO 37-S2 | 5 |
| Elongation at break [%] | ISO 37-S2 | 300 |
The advantages and material properties of NR/SBR at a glance
In addition to the named properties, the NR/SBR rubber has good compressive strength and good resistance to acetone and alcohol. Styrene-butadiene rubber is also considered to have excellent resistance to water and steam. Furthermore, the material is very ductile and shock-elastic. In addition, the temperature resistance is considered to be good. This makes this material suitable for many areas of application.
NR/SBR owns:
- High elasticity
- High cold flexibility
- High tensile strength
- High abrasion resistance
Only moderate resistance to numerous chemicals as well as alkalis and acids can be assumed. NR/SBR is also unsatisfactory in terms of its ageing resistance and resistance to ozone and UV light. The material is also not recommended with regard to fuels or cleaning agents containing solvents.
NR Permanencies at a glance
| Material designation | Ozone and weather resistance | Oil and petrol resistance | Acid resistance | Strong bases | Wear resistance |
| Semperit SBR A 9506 | not durable | not durable | constant | conditionally stable | Not suitable |
| Semperit NR-SBR A 618 | not durable | not durable | conditionally stable | constant | conditionally stable |
| Semperit NR-SBR A 621 | not durable | not durable | conditionally stable | constant | conditionally stable |
| Semperit NR SBR A 590 | not durable | not durable | conditionally stable | constant | well suited |
| Semperit Para NR A 160 | not durable | not durable | conditionally stable | constant | well suited |
| Semperit Para NR 560 | not durable | not durable | conditionally stable | constant | well suited |
Application areas of NR/SBR gaskets
NR/SBR seals can be used for hydraulic and pneumatic applications where high mechanical wear due to friction is to be expected. The interior of buildings or housings as well as UV-protected outdoor areas can be highlighted as a further area of application. Furthermore, the material is suitable as wear protection, abrasion protection as well as impact protection.
We will be happy to answer your questions about whether NR is also suitable as a sealing material for your purposes. Please contact our customer service, who will be happy to provide you with comprehensive advice.